"use strict";

/**
 * 巡检报告快照存储
 *
 * 每次 runReportSnapshot 生成一条快照：
 *
 *   {
 *     id,            // "snap_<ts>_<rand>"
 *     timestamp,     // 快照生成时间
 *     duration_ms,   // 整体耗时
 *     trigger,       // "manual" | "scheduled"
 *     devices: [     // 每台设备的报告
 *       {
 *         device_id,
 *         hostname,
 *         catalog_id,
 *         ok,              // 设备上所有命令都 ok = true
 *         duration_ms,
 *         commands: [      // 每一条命令的执行结果
 *           { cmd, purpose, ok, duration_ms, stdout, stderr }
 *         ]
 *       }
 *     ]
 *   }
 *
 * 为避免 JSON 无限膨胀，MAX_SNAPSHOTS 条整体保留，每条设备 stdout 截断 MAX_CMD_STDOUT 字符。
 */

const { STORAGE_KEY_REPORT_SNAPSHOTS } = require("./storageKeys.cjs");

const MAX_SNAPSHOTS = 200;        // 保留最近 200 次快照
const MAX_CMD_STDOUT = 4000;      // 单条命令 stdout 保留前 4000 字符（display logbuffer 可能 10k+）

let _snapshots = null;

function _safeParse(text, def) {
  if (text === null || text === undefined) return def;
  if (typeof text === "object") return text;
  try { return JSON.parse(text); }
  catch { return def; }
}

function _ensureLoaded(readFn) {
  if (_snapshots === null) {
    const raw = readFn(STORAGE_KEY_REPORT_SNAPSHOTS);
    _snapshots = raw ? _safeParse(raw, []) : [];
  }
}

function _save(writeFn) {
  if (_snapshots.length > MAX_SNAPSHOTS) {
    _snapshots = _snapshots.slice(-MAX_SNAPSHOTS);
  }
  writeFn(STORAGE_KEY_REPORT_SNAPSHOTS, JSON.stringify(_snapshots));
}

function _truncate(text, max = MAX_CMD_STDOUT) {
  if (!text) return "";
  if (text.length <= max) return text;
  return text.slice(0, max) + `\n... [truncated ${text.length - max} chars]`;
}

// ---------- 增删改查 ----------

/**
 * 新增一条快照。snapshot.devices[].commands[].stdout 会自动截断。
 */
function addSnapshot(readFn, writeFn, snapshot) {
  _ensureLoaded(readFn);

  // 自动截断 stdout
  const cleanDevices = (snapshot.devices || []).map(d => ({
    ...d,
    commands: (d.commands || []).map(c => ({
      ...c,
      stdout: _truncate(c.stdout || ""),
      stderr: _truncate(c.stderr || "", 500),
    })),
  }));

  const record = {
    id: snapshot.id || `snap_${Date.now()}_${Math.random().toString(36).slice(2, 8)}`,
    timestamp: snapshot.timestamp || Date.now(),
    duration_ms: snapshot.duration_ms || 0,
    trigger: snapshot.trigger || "manual",
    devices: cleanDevices,
  };

  _snapshots.push(record);
  _save(writeFn);
  return { ...record };
}

/**
 * 列出快照（新的在前）
 */
function listSnapshots(readFn, limit = 50) {
  _ensureLoaded(readFn);
  return [..._snapshots].reverse().slice(0, limit);
}

/**
 * 按 id 查单条快照
 */
function getSnapshot(readFn, id) {
  _ensureLoaded(readFn);
  return _snapshots.find(s => s.id === id) || null;
}

/**
 * 删除一条快照
 */
function deleteSnapshot(readFn, writeFn, id) {
  _ensureLoaded(readFn);
  const before = _snapshots.length;
  _snapshots = _snapshots.filter(s => s.id !== id);
  if (_snapshots.length < before) {
    _save(writeFn);
    return true;
  }
  return false;
}

/**
 * 清空所有快照
 */
function clearAll(readFn, writeFn) {
  _ensureLoaded(readFn);
  _snapshots = [];
  _save(writeFn);
}

/**
 * 统计概览（用于日运行报告聚合）
 */
function summarize(readFn, sinceTs) {
  _ensureLoaded(readFn);
  const snaps = _snapshots.filter(s => s.timestamp >= sinceTs);

  let totalDevices = 0;
  let totalCmds = 0;
  let okCmds = 0;
  let failedCmds = 0;
  const failedDevices = new Set();

  for (const snap of snaps) {
    for (const dev of snap.devices || []) {
      totalDevices++;
      for (const cmd of dev.commands || []) {
        totalCmds++;
        if (cmd.ok) okCmds++;
        else { failedCmds++; failedDevices.add(dev.device_id); }
      }
    }
  }

  return {
    snapshot_count: snaps.length,
    total_device_checks: totalDevices,
    total_commands: totalCmds,
    ok_commands: okCmds,
    failed_commands: failedCmds,
    failed_device_ids: Array.from(failedDevices),
  };
}

/**
 * 标记快照 AI 分析状态（running 主进程在跑、done 成功、failed 失败）
 */
function setSnapshotAiStatus(readFn, writeFn, snapshotId, status, error) {
  _ensureLoaded(readFn);
  const snap = _snapshots.find(s => s.id === snapshotId);
  if (!snap) return false;
  snap.ai_summary_status = status; // "running" | "done" | "failed" | undefined
  if (error) snap.ai_summary_error = error;
  else delete snap.ai_summary_error;
  if (status === "running") {
    delete snap.ai_summary;
    delete snap.ai_summary_updated_at;
  }
  _save(writeFn);
  return true;
}

/**
 * 更新快照的 AI 汇总（AI 成功分析后存回，status 自动设为 done）
 */
function updateSnapshotAiSummary(readFn, writeFn, snapshotId, aiSummary, error) {
  _ensureLoaded(readFn);
  const snap = _snapshots.find(s => s.id === snapshotId);
  if (!snap) return false;
  if (error) {
    snap.ai_summary_status = "failed";
    snap.ai_summary_error = error;
    delete snap.ai_summary;
  } else {
    snap.ai_summary_status = "done";
    snap.ai_summary = aiSummary;
    snap.ai_summary_updated_at = Date.now();
    delete snap.ai_summary_error;
  }
  _save(writeFn);
  return true;
}

/**
 * 清空快照的 AI 汇总（用于重试前清除旧结果）
 */
function clearSnapshotAiSummary(readFn, writeFn, snapshotId) {
  _ensureLoaded(readFn);
  const snap = _snapshots.find(s => s.id === snapshotId);
  if (!snap) return false;
  delete snap.ai_summary;
  delete snap.ai_summary_updated_at;
  _save(writeFn);
  return true;
}

function _resetForTest() { _snapshots = null; }

module.exports = {
  MAX_SNAPSHOTS,
  MAX_CMD_STDOUT,
  addSnapshot,
  listSnapshots,
  getSnapshot,
  deleteSnapshot,
  clearAll,
  summarize,
  setSnapshotAiStatus,
  updateSnapshotAiSummary,
  clearSnapshotAiSummary,
  _resetForTest,
};